times =0
while times <= 3:

    guess_number = int(input("请输入分数："))

    if  guess_number>100:
        print("输入错误，满分100")
    elif guess_number >= 90:
        print("等级：A")
    elif guess_number >= 80:
        print("等级： B")
    elif guess_number >= 60:
        print ("等级：C")
    elif guess_number >= 40:
        print("等级 D")
    else:
        print("E")
        
    times += 1